My model 3 was in the shop for a week and I was given a model s loner car and noticed it charges at a rate of 19 miles per hour of charge while my model 3 charges at a rate of 30 miles per hour. This is off of 240w/32a. I was wondering how this different charging rate effects my electricity bill? Is energy used calculated per hours pugged into the outlet? or the amount of energy produced? In other words since 3 hours of charge on my M3 gets me 90 miles while it would take around 4.5 hours of charge on the model s to gain the same 90 miles, is the MS costing me more to charge than the M3?